1. Field of the Invention
The present invention relates to a system for subscriber loop testing and, more particularly, to such a system used in a telecommunications network having fiber extending to the curb. The system is designed to implement Mechanized Loop Testing (MLT).
2. Description of the Prior Art
Optical fibers are rapidly becoming the preferred means for transmission in telecommunications systems. The advantages of using optical fibers are well known and are fully accepted as being desirable. Optical fiber transmission provides exceedingly wide bandwidths which will allow for the future provision of broadband services directly to individual subscribers on a relatively universal basis. Such broadband services may include data transmission; however, there is a broader market for the distribution of video services over the telecommunications network to the vast number of residential subscribers.
There have been many proposals to provide optical fiber networks; however, in most cases the cost of providing fiber directly to the home or to remote areas of the network proved to be prohibitive. Thus, fiber has been proposed for use in feeder trunks, and even for further distribution down to some remote unit closer to the actual subscriber. At such a remote unit, the typical line cards would be used for providing twisted pair metallic drops to the actual subscriber.
Once line cards migrate to a remote unit, the cost of providing a remote test unit, as used in Digital Loop Carrier (DLC) remote housings, becomes prohibitive. A recent Bellcore Technical Advisory TA-NWT-000909 requires that certain line faults be tested for, with the results transmitted to a Remote Measurement Unit (RMU) in the form of a series of resistor signatures. Thus, any fiber optic transmission network architecture that will be commercially accepted must have provisions that satisfy this Bellcore Technical Advisory.